Fuel burner



' A. H. SHAW FUEL BURNER Sept. 21 1926.

- Filed Feb. 13, 1926 IN VENT 0R.

Patented Sept. 21, 1926.

' UNITED STATES PATENT: oF c ALEXANDER I-I. SHAW, or MIDWEST, WYOMING.

FUEL BURNER.

Application filed February The present invention relates to improvements in fuel burners of the type wherein a blast or current of air is intimately mixed with fuel gas to produce a mixture adaptable for complete combustion.

Animportant object of the invention is A 'to provide a burner of the above character of comparatively simple yet eflicient design and gas will be uniformly mixed and at the same time present-a structure designed to prevent premature destruction, by the intense heat. r

A still further object of the invention is the provision of a burner adaptable for firing furnaces and the like which will be efficient inuse and can be manufactured at'a comparably low cost.

Other objects and advantages of the invention will become apparent as the description progresses.

"In the accompanying drawing forming a part of'this specification and in which like numerals are employed to designate corresponding parts throughout the same:

Figure 1 is an end elevation of my -improved burner structure taken from the interioruofthe combustionichamber,and V Figure 2 is a transverse 'sectionaluview taken on the line 2-2 of Figure 1.

Referring to the drawing, wherein for the, purpose of illustration is shown the preferred embodiment ofv my invention, the numeral, 10 generally designates a fragmentary portion of a wall of a combustion chamber provided with an annular opening for the introduction of a fuelburner'; My invention contemplates the provision of an air duct 11 adapted to be arranged snugly in, the opening ofthe combustion. chamber wall 7 having a uneven inner contour through which a current of air is injected. Arranged centrally intheair duct 11 is a gas burner generally indicated bythe nu- ,meral12, through which the fuel gas isdistributed for mixture with the air in suitable proportion to produce complete combustion.

Referring now more specifically to the construction embodying my invention, it'

13, 1926. Serial No. 88,062.

will be readily noted that the air duct 11 is of generally tubular formation and ma be of metallicconstruction or, if desirable, may be formed of refractory material. The outer surface of the duct 11 may be of uni form cylindrical formation and arranged so as to be tightly fitted within the opening in the wall of the. combustion chamber. The

inner bore of the air duct is formed to provide a passage of decreased area adjacent" the inner extremity, the purpose'of which will become apparent as the description progresses. This is accomplished, -in. the present instance, by forming the duct with an interior annular ridge 13 having an abrupt shoulder at the intermediate portion of the air duct and gradually tapering to-' ward the innerextremity which is rounded as at 14.. From this construction, it is apparent, that the current of air passing through the air duct will bedirected toward the center of the duct adjacent the innerextremity and is thus mixed gas, as will be presently seen. V v H Mounted so as to'maintain acentral position in the vduct adjacent the inner end thereof is theburner 12 embodying alongitudinally extending gas supply pipe 15 supported in. anyzgconventional manner. and communicating'with a gas producer or any source of supply. The inner discharge end .with the of this supply. pipe which is of tubular formation, is of heavier construction to provide a nozzle 16, beveled .at its extremity as at 17 and provided adjacent its oppositejend with .external screw threads 18.

Arranged to be. threadedly mounted on the a nozzle 16 and generally enclose the same is a bulbous oval shaped shell 19, one end thereof being open and provided ,withinternal screw threads adapted for engagement with the threads 18 formedon the nozzle. As can be readily noted, with reference to Figure 2 of the drawing, an interior ring 20 is formed adjacent the open end of the shell to provide a durable structure for the formation oflthe threads. A transversely extending screw threaded bore 21 7 is formed; through the reinforcing ring 20 and is adapted to engage a .sets crew for secure connection of the shell upon the nozzle. In order to permit suitable discharge of the fuel gas, the I shell 19 is provided with. a plurality of orifices or apertures 22 preferably formed in forwardly directed angular. positions ,as shown to advantage Figure 2. Theseoriiii fices may be arranged in equal spaced relation in circular formation in the intermediate portion of the shell as shown, or in staggered relation as foundthe most suitable for the efficient operation of the burner. It is readily evident, from the foregoing, that the particular relation of the shell upon the nozzle provides an expansion chamber for the fuel gas as the. same issues'from the nozzle and, an adjustable air passage is formed between the beveled end portion of the nozzle and the inner closed end of the shell.

In operation, it will be seen that as the current of air passes through the air duct 11 the air in its movement induces a flow gas through the orifices22 formed in the burner shell 19. Due to the arrangement of the burner in the air duct, the air and gas will be uniformlyinixed as the gas is intro duced into the air stream in the restricted area of the duct and thus produces an intimate mixture. As the gas issues from the discharge end of the nozzle and is circulated in the chamber formed by the shell, the expansion of the gas will result in a decrease in temperature. A similar effect is produced by the deflected current of air striking the outer surface of the shell. Assuming that a comparatively large proportion of gas is desired during a certain period of operation of the burner, this can be readily effected by turning the set screw threadedly mounted in the opening 21 of the shell so as to disengage the threads 18 formed on the nozzle, and the shell '19 suitably rotated to move the shell inwardly relative to the nozzle, or in a remote position from the end thereof. This will increase the area of the annular passage between the beveled end of the nozzle and the shell so that an increased flow of fuel gas is permitted into the expansion chamber formed by the shell and discharged through the orifices. The set screw is then screwed tightly into position in engagement with the nozzle to prevent further movement of the shell so that the predetermined mixture may be uniformly maintained. To reduce the proportion of the gas necessary for the complete combustion reverse rotary movement of the shell will reduce the amount of gas discharged for mixture with the air so that a greater proportion of air is employed in the mixture.

As will be readily noted, by those familiar with this art, a burner of improved design has been devised, providing means for producing an intimate mixture of air and gas to obtain complete combustion, and presenting a structure whereby unrestricted passage of the fuel is afforded. The particular formation and relative arrangement of the air duct and burner will cause the mixture of the air and gas to take place in a reduced portion of the air passage so that a thorough mixture is obtained and the utmost efiiciency of the fuel effected.

It is to be understood that the form of my invention herewith shown and described is to be taken as the preferred example of the same and that various changes as to the shape, size and arrangement of parts may be resorted to without departing from the spirit of the inventionor the scope of the subjoined claims.

Having thus described my invention, I claim 'i 1. In a fuel burner, a supply pipe, a mem ber adjustably associatedwith the supply pipe and arranged to provide an expansion chamber about the discharge end thereof, the said member being provided with a plurality of discharge orifices, and an air duct arranged in spaced relation laterally 0f the supply pipe provided with an annular inwardly projecting ridge adapted to form a restricted passage adjacent the orifices formed in the said 'adjustablemember. V

2. In a fuel burner, a supply pipe, a shell adjustably mounted on the supply pipe and arranged to form an expansion chamber about the discharge end thereof, the said shell being provided with a plurality of dis charge orifices, and an air duct offannular formation arranged in spaced axial position relative to the supply pipe and shell provided with an annular ridge arranged to form a reduced passage adjacent the dis charge orifices formed inthe shell.

3. In a fuel burner, the combination of a burner including a discharge nozzle and an adjustable shell positioned aboutv the discharge opening of the nozzle provided with discharge orifices, and an air duct arranged in spaced relation about the nozzle and shell provided with an annular interior ridge arranged to form a reduced passage adjacent the discharge orifices of the shell to form an intimate mixture of the fuel and air.

4. In a fuel burner, a supply pipe, a discharge nozzle formed on one end of the suply pipe, a shell of enlarged formation adjustably fitted about the discharge end of the nozzle, means for fastening the shell in adjusted position on the nozzle, the said shell being provided with a plurality of angular. directed discharge orifices, and an air duct including a cylindrical tube arranged in axial spaced relation about the nozzle and shell having an annular inwardly extendin ridge formed adjacent the orifices foi med in the shell, the said ridge tapering toward the inner end of the duct for efficient passage'of the mixture.

5. The combination with the combustion chamber of a furnace having an opening in the wall thereof, of a burner including a supply pipe, a shell arranged in spaced re lation about the discharge end of the supply pipe, means for adjustably actuating the shell in axial position relative to the discharge opening of the supply pipe, and adjustable means adapted to permit securing of the shell in adjusted position upon the discharge pipe; and an air duct of cylindrical formation arranged to be snugly fitted in the opening of the combustion cham- 7 her and provided with an annular inwardly projecting ridge adapted to direct the air blast in a reduced passage adjacent the dis charge orifices of the burner shell. I

6. In combination With a combustion chamber having an opening in one Wall thereof, and an air duct snugly fitted in the opening provided With an annular interior ridge; a urner including a supply pipe arranged in a central axial position in the air duct, a shell of generally oval formation threadedly mounted adjacent thedischarge end of the supply pipe arranged to form an expansion chamber about the discharge end of the pipe and-adjustable relative to the discharge opening, means for locking the shell in adjusted position uponthe supply pipe, the said shell being provided With a plurality of angular directed orifices ar- 

